Nowadays, helium leak tests are largely used by many companies around the world to check the presence of leaks in their products and avoid problems arising. Helium is utilized because it has the smallest atom among the known elements and so it is perfect to detect even the smallest leaks. Beyond that, it is inert, and it is not dangerous as for example hydrogen. The most common type of sensor used to measure the helium concentration is the so called "thermal conductivity detector". It’s a device that computes the concentration using the difference of thermal conductivity between a carrier gas and a mixture of the carrier gas and column effluent gas.